From: Amir Vadai Date: Mon, 7 Oct 2013 11:38:13 +0000 (+0200) Subject: net/mlx4_en: Fix pages never dma unmapped on rx X-Git-Tag: firefly_0821_release~176^2~5117^2~56^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=021f1107ffdae7a82af6c53f4c52654062e365c6;p=firefly-linux-kernel-4.4.55.git net/mlx4_en: Fix pages never dma unmapped on rx This patch fixes a bug introduced by commit 51151a16 (mlx4: allow order-0 memory allocations in RX path). dma_unmap_page never reached because condition to detect last fragment in page is wrong. offset+frag_stride can't be greater than size, need to make sure no additional frag will fit in page => compare offset + frag_stride + next_frag_size instead. next_frag_size is the same as the current one, since page is shared only with frags of the same size. CC: Eric Dumazet Signed-off-by: Amir Vadai Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 066fc2747854..afe2efa69c86 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -135,9 +135,10 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv, int i) { const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i]; + u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride; - if (frags[i].page_offset + frag_info->frag_stride > - frags[i].page_size) + + if (next_frag_end > frags[i].page_size) dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size, PCI_DMA_FROMDEVICE);